This article is a quick example of how to add a system call to OpenBSD. The following description is based on OpenBSD 3.4-beta on i386 machine architecture. Also, it is assumed that readers are familiar with building the OpenBSD kernel.

This article describes how the m88k-specific backend of the GNU C compiler, gcc, was fixed, from the discovery and analysis of the problems to the real fixing work. Since it started with almost zero gcc internals knowledge, it should be understandable by anyone able to read C code, and proves that diving into gcc is not as hard as one could imagine.